Lightning-arrester for fire-alarm boxes



(No Model.)

R. HUDIE. LIGHTNING ARRESTER FOR FIRE ALARM BOXES.

Patented Sept. 30. 1890.

1 a w n a Q 7 a UNITED STATES PATENT OFFICE.

ROBERT IIUDIE, OF ALLEGHENY, PENNSYLVANIA.

LIGHTNING-ARRESTER FOR FIRE-ALARM BOXES.

SPECIFICATION forming part of Letters Patent No. 437,397, dated.September 30, 1890.

Application filed June 11, 1890- Serial No. 3 5,04 (N M19 T0 on whom itmay concern:

Be it known that I, ROBERT HUDIE, a resident of Allegheny, in the countyof Allegheny and State of Pennsylvania, have invented a new and usefulImprovement in Lightning-Arresters for Fire-Alarm Boxes; and I do herebydeclare the following to be a full, clear, and exact descriptionthereof.

My invention relates to fire-alarm-telegraph boxes, its object being toprovide for cutting off the electric connection of the wires leading tothe box from the coils operating the mechanism therein, so that suchoperative mechanism is only brought into electric connection when it isutilized to give the necessary signal, this being the only time when itis required to be in circuit. In the ordinary construction of theseboxes and in the ordinary firealarm systems the line -wire leads fromsignal-box to signal-box, the electric connection being carried throughthe mechanism of the box, and as a consequence in case of any heavycurrent in the wire-such as from lightning or from accidental electricconnection with electric-light or electric-motor wiresthe high currentis carried through the coils of the automatic-alarm apparatus within thefire-alarm boxes and acts to burn them out, so destroying the coils andnecessitating the replacing thereof. As such accidents are liable tooccur at any time and may render the signal apparatus useless, and asthe boxes are only employed in cases of emergency, it is thus seen to beof great importance to prevent the passing of any such currents throughthe coils of the apparatus and the destroying of the same; and theobject of my invention is to overcome this difliculty.

To these ends my invention consists, generally stated, in combining withthe ordinary switch-board a fire-alarm apparatus provided with aspring-key normally in circuit, acrosskey extending from one pole to theother of the apparatus and adapted when pressed down to cut the coils ofthat particular signaling apparatus out of circuit, this crosscut-key,as I have termed it, by connecting the two poles of the battery, forminga circuit through the same, and so in no way interfering with theregular circuit through the box in which that particular signalingapparatus is located.

extends.

To enable others skilled in the art to make and use myinvention, I willdescribe the same more fully, referring to the accompanying drawings, inwhich Figure l is a face view of the fire-alarm switch-board having myinvention applied thereto. Fig. 2 is an enlarged face View of the same.Fig. 3 is a side view of the same. Fig. 4 is an enlarged sectional viewof a part of the signalingbox when closed, showing the means employed tooperate the crosscut-key; and Fig. 5 is a detail view showing the c011-nection of the operating-pin with the door and the manner of operatingthe same.

Like letters of reference indicate like parts in each figure.

As the operative mechanism of the signaling apparatus forms no part ofthe present invention, I will not describe the same, but will simplydescribe the ordinary switchboard and the application of my improvementsin connection therewith. The switch-board ahas the pole-plate 19,provided with the bindingpost Z), to which the line-wire c connects, andwith the post W, from which the wire 19 extends to the coils of thesignaling apparatus.

For convenience of description the plateb will be called the positiveplate. On the other side of the switch-board is the plate (I, which maybe termed the negative plate, that plate having the binding-post (l, towhich theline-wirefisconnected. Thenegativeplate (Z has formed thereonthe spring-key g, which is held normally in contact with the plate h,having the binding-post 7t thereon, to which the wire 7L2 leads from thecoils of the signaling apparatus. As so constructed it is evident thatthe current through the entire system passes through the coils of thesignaling apparatus in each particular box, the springkey g being simplyemployed in the box for signaling purposes in case any person connectedwith the fire-department desires to signal to the central oflice.Between the plates 1) and (Z is the lightning-arrestert, from thebinding-post t" of which the ground-wire Extending across from the plateI) to the key g is what I have termed the crosseut-key 75, this keybeing a springkey, which is normally raised out of circuit, but can bedepressed so as to be forced into contact with the spring-key g andforce said IOC spring-key out of contact with the plate h, so cuttingout from the circuit the coils of the fire-alarm apparatus in thatparticular box. When the crosscut-key 7c is depressed, while it cuts outthe coils of the signaling apparatus in that box it also forms across-cut from the pole-plate I) over to the pole-plate d, so that theregularcircuit through the line-wire will be maintained through thiscross-cut key.

For the purpose of operating the crosscutkey and causing it to depressthe spring-key g when the box is closed I preferably employ a pin m,which is secured to the outer door of the box and extends throughanopening 1 in the inner door thereof, said opening being in line with thecrosscut-key 70, so that when the outer door is closed the pin m bypressing upon the key will force it into contact with the spring-key gand force that key out of contact with the plate h. This pin 'm ispreferably hinged to the outer door at, as at p, and when the outer dooris opened, in order to obtain access to the signaling lever or. buttonwhich extends through the inner door, the pin m is withdrawn and thecrosscut-key springs back out of contact with the spring-key g andpermits that key to form contact with the plate It, so establishing thecircuit through the coils of the signaling apparatus in that box, thecoils of the signaling apparatus being thus automatically brought intocircuit. The apparatus thus acts to cut out the coils of the signalingapparatus, except when signaling from that particular box; and ittherefore follows that in case of severe current upon the line-wireinstead of this being permitted to pass through the signaling apparatusof one or more boxes and to burn them out its only action is to passthrough to the pole-plates and thence out of the box, being finallydisseminated through the lightning-arresters in the different boxes andcan riedtotheground,noharmbeing done thereby.

In order to render it easy to enter the pin 'm through the inner door, Igenerally form in the end thereof a keyway r and in the outer door *a alike keyway r, through which keyways a suitable key maybeinserted bywhich the pin can be held in its raised position, and as soon as the pinenters the holel in the inner door it will be directed therebyinto suchposition as to bear upon the crosscut-key is, bringing it into contactwith the spring-key and forcing the spring-key out of contact with theplate h, as above described.

What I claim as my invention, and desire to secure by Letters Patent,is-

1. The combination,with afire-alarm switchboard having a spring-keythereon normally in circuit, of a spring-operated crosscut-key extendingfrom one pole-plate above the springkey to the other pole-plate, wherebywhen the crosscut-key is pressed down the line is closed between thepole-plates through the crosscutkey and the operating-coils of thealarm-box are cutout of circuit, substantially as and for the purposesset forth.

2. The combination of a fire-alarm switchboard having one pole-platethereof provided with a spring-key normally in circuit, aspring-operated crosscut-key extending from the other pole-plate abovesaid spring-key, whereby when the crosscut-key is pressed down the lineis closed, and a pin secured to the doorof the apparatus and adapted topress down the crosscut-key, substantially as and for the purposes setforth.

3. The combination of a fire-alarm switchboard having one pole-plat-ethereof provided with a spring-key normally in circuit, a

spring-operated crosscut-key extending from the other pole-plate aboveand adapted when pressed down to cut out said spring-key, and a pinsecured to the door of the apparatus and adapted to press down thecrosscut-key, said pin being hinged to the outer door and adapted topass through the inner door, substantially as and for the purposes setforth.

4. A combination of a fire-alarm switchboard having one pole-platethereof provided with a spring-key normally in circuit, aspring-operated crosscut-key extending from the other pole-plate aboveand adapted when pressed down to cut out said spring-key, and a pinsecured to the door of the apparatus and adapted to press down thecrosscut-key, said pin being hinged to the outer door and adapted topass through the inner door and provided with a keyway in the endthereof and said door having a keyway in line with the keyway of thepin, substantially as and for the purposes set forth.

In testimony whereof I, the said ROBERT HUDIE, have hereunto set myhand.

J. N. OooKE, ROBT. D. .TOTTEN.

